Field of the Invention
The present invention relates to a particles manufacturing method, and in particular to a silver particles manufacturing method.
The Prior Arts
Presently, silver particle, especially nm-scale silver particle is the major material utilized extensively in producing solar cells, printed circuit boards, and other photo-electronics related industries. Due to its advantages of having large surface area, the functions and capabilities of the nm-scale silver particles are raised significantly. As such, it has been used in producing products of various applications, such as conductive printing ink, electronic products, cosmetics, medical products, textiles, paint, pigment, spraying material. Since the price of silver particle is high, and it is used in large quantity in the Industries, in case a silver particles producing method can be developed, capable of achieving low cost, zero pollution, and high yield, then it could reduce the production cost significantly for the industries requiring to use large amount of conductive silver glue, in raising the competitiveness of their products.
In the conventional technology, quite a lot of methods are available for producing silver particles. For example, chemical reduction method, high temperature thermal reduction method, electrochemical reduction method, microwave reduction method, hydrothermal reduction method, biological reduction method, and radiation exposure method. Wherein, the chemical reduction method is used most extensively, while the reduction agent used most frequently are sodium borohydride, tri-sodium citrate, and aniline, etc. In the electrochemical reduction method, silver electrode and platinum electrode are utilized to perform reduction of nm-scale silver particles through electrolysis. In the biological reduction method, microorganism and plant leaf extract fluid are utilized as reduction agent. Further, in the radiation exposure method, radiation such as ultraviolet light, microwave radiation, or stray radiation are used to perform reduction of nm-scale silver particles.
However, the silver particle manufacturing methods mentioned above all have their problems and shortcomings. For example, the reduction agent utilized in the chemical reduction method are highly toxic and dangerous. The high temperature thermal reduction method has to be performed in a reduction atmosphere of hydrogen in a temperature of over 500° C., that is highly dangerous and waste of energy. The electrochemical reduction method requires to use large amount of electrolysis fluid, such that it consumes large amount of electricity, while its yield is low. For the rest of the reduction methods for producing nm-scale silver particles, they have the drawbacks of having complicated steps or requiring to use devices that could cause radiation hazards.
Therefore, presently, the design and performance of the silver particles manufacturing method is not quite satisfactory, and it leaves much room for improvement.